This report presents the results obtained from an experimental study of the variability inherent in measurements of total sulfation, using ASTM Method D 2010(1). The evaluation of Method D 2010 was performed as part of the first phase of Project Threshold, a comprehensive program to validate ASTM methods for measuring various atmospheric contaminants. In addition, methods for measuring the content of nitrogen dioxide (D 1607), sulfur dioxide (D 2914), lead (D 3112), dustfall (D 1739), and particulate matter (D 1704) in the atmosphere have also been evaluated during Phase 1. |